This invention relates to a waterproof seal construction for a wire harness having a branch connecting portion intermediate opposite ends thereof and having waterproof connectors connected respectively to the opposite ends thereof.
In the type of wire harness (automotive wiring) in which a waterproof connector and a branch connection are used, when water enters a wire due to an incomplete waterproof treatment, the water intrudes into the waterproof connector because of a suction phenomenon due to a temperature difference of the waterproof connector. As a result, the overall waterproof effect of the wire harness is lowered.
FIG. 7 shows one example of wire harness of such a construction. The wire harness W comprises an electrically insulatively-covered wire 1, and the covering or sheath is removed from the wire 1 intermediate the opposite ends thereof to expose conductors 1a. Another wire 1' is branch-connected to the thus exposed portion of the conductors 1a by the use of a crimp-style terminal 2. A waterproof seal 3 is provided on this branch connecting portion either by winding a tape, such as a PVC tape and a butyl rubber tape, on this branch connecting portion or by applying a molding of PVC to this branch connecting portion. A waterproof connector 4.sub.1 of the female type is connected to one end of the wire 1. A male terminal 7 press-connected to the end of the wire 1 is inserted in a terminal receiving chamber 6 of a connector housing 5, and a rubber plug 8 fitted on the wire end portion is fitted in the receiving chamber 6. The waterproof connector 4: is fitted on a waterproof connector 4' of the male type through a packing (not shown). Similarly, waterproof connectors 4: and 4: of the female type are connected to the other end of the wire 1 and the end of the wire 1', respectively. These ends of the wires 1 and 1' may be connected to one waterproof connector 4.sub.2 or 4.sub.3.
As will be appreciated from FIG. 7, if the branch connecting portion where the waterproof seal 3 is provided is defective, the water intruding into the wire harness from this portion would cause corrosion of the contact between the female and male terminals of the waterproof connectors 4.sub.1 and 4.sub.2 and 4.sub.3 and also corrosion of that portion press-clamped to the wire. Further, this adversely affects the electrical insulation between the adjacent terminals.